Berlin 2018 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 36: Topical Session (Symposium MM): Fundamentals of Fracture

MM 36.4: Vortrag

Mittwoch, 14. März 2018, 12:30–12:45, TC 006

Modelling Chemomechanical Materials Failure Processes in SiC and Diamond — •Punit Patel and James Kermode — University of Warwick, United Kingdom

Atomistic simulations of crack propagation are key to understanding the fracture behaviour of materials. Cracks involve strong coupling across the scales, with bond breaking on the quantum scale driven by long range stress fields. Current QM methods are limited to simulation sizes too small to accurately describe fracture dynamics and improved QM/MM methods are able to adequately capture elastic effects [1]. However these methods are still heavily limited temporally and to coarse grain into the continuum scale while maintaining the overall fracture dynamics an expanded multiscale approach is required.

Applications in covalently bonded single crystals to complex alloys are underway. Screened classical potentials [2] predict a brittle response in both silicon carbide (SiC) and diamond, giving confidence in their applicability. DFT SiC surface energy calculations produced predictions in good agreement with experiment [3]. Extension of the multiscale approach for fracture includes a novel approach in correcting for finite domain boundary conditions in order to compute energy barriers for crack extension bridging DFT and long time scale MD.

[1] N. Bernstein et al., Rep. Prog. Phys. 72, 026501 (2009).

[2] L. Pastewka et al., Phys. Rev. B. 87, 205410 (2013).

[3] G. Sernicola et al., Nat. Commun. 8, 108 (2017)